Humans are very good at dealing with stress, especially when you compare to other animals. Looking at you, giraffe.

However, large parts of human society is actually built on the assumption that, by and large, humanity will rise to the challenge. We push everything to its limit, then pick up the pieces and make adjustments when it breaks. Why? Because that's what the previous winners did, and we are all descendants of winners.

Of course, some won bigger than others...

You won't get a rash. In fact, exposing the area underneath to the elements is more likely to lead to a rash.

Medieval Europeans did a lot of dying in the winter. Old people, very young people...

A lot of the winter survival tricks are either not viable or no longer worth it. The solutions of today are better, it's just a matter of getting enough consensus, in most cases.